Propulsion mechanism for watercraft



Oct 6, 1936.

Original Filed May 13, 1933 2 Shets-Sh eet l INVENTOR.

Oct 6, 1936. X 7 2,056,475

' PROPULSION MECHANISM FOR WATERCRAFT Original Filed May 13, 1933 2 Sheets-Sheet 2 I INVENTOR.

Patented Oct. 6, 1936 PATENT OFFICE PROPULSION MECHANISM FOR WATERCRAFT Karl F. Marx, Dearborn, Mich.

Application May 13, 1932, Serial No. 670,936 Renewed March 2, 1936 2 Claims. (01. 115-21 The present invention relates to propulsion mechanism for water craft and more especially to means for transforming muscular energy into propulsive power by mechanical means.

Among the objects of the invention is means to take the place of hand operated oars which are open to many objections and provide a builtin driving means entirely within the boat structure and operable by either hand or foot power, preferably the latter.

Another object is driving means which shall be very much more efficient than the ordinary oar.

Still other objects and advantages will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which Figure 1 is a longitudinal sectional view of the present device.

Figure 2 is a plan view showing the pistons with their cable connections.

Figure 3 is a partial cross sectional view of one of the pistons in return position with flapper valves open.

Figure 4 is a partial cross sectional view of one of the channels and the piston with flapper valves closed ready for propelling action.

Figure 5 is a cross sectional View on line A--A of Figure 1.

Figure 6 is a view of another pedal construction.

Figures 7 and 8 show modified forms of driving means.

Figure 9 is a side view of a modified piston, and

Figure 10 is an end view of the same.

Like characters of reference are employed throughout to designate the corresponding parts.

In the drawings the numeral I indicates the hull of the boat having as integral parts there-. in cylindrical channels constructed below the water line with both ends open. As indicated in the drawings the cylinders 2 may be placed in a double bottom construction and thus out of the way of boat occupants. In the present device I employ two pistons 3, one in each cylinder, alternating between power stroke and return travel although one piston alone can 'also be used. Inside said pistons are flapper valves 8 hinged to a suitable pin l8 fixed in the piston walls. On the power stroke these valves are closed and rest with the ends against suitable stops 1 to restrict the flow of water through the piston, thereby pushing the water back through the channel 2, at the same time causing suction at the other side of said valves as means for propulsion of the craft. On the return stroke said valves open up and because of near streamline construction offer little resistance to water-flow through said pistons.

At the rear of each of the pistons a cable or rope 4 is attached and is guided over suitable roller sheaves or pulleys 5 and 6, to be attached tothe front end l2 of the lazy tongs II. From the front end of one piston another cable or rope 10 I4 travels over other roller sheaves l5 to the front end of the other piston.

The lazy tong mechanism H on each side of the craft have each a fixed fulcrum 9 and a pedal It. By pushing upon pedal Ill said mecha- 5 nism expands and as the pull cable 4 of the piston is attached at the front end l2, a longer travel of cable 4 is created than the foreward motion of the pedal Ill. The location of the pedal 1 ll may be changed if desired. For instance if pedal I0 is brought closer to the front end l2 the stroke of the operators leg I6 is naturally greater but less power is necessary than would be the case if the pedal were fastened closer to the fixed fulcrum 9.

The channel I! guides and protects the lazy tong mechanism. The operator's seat is indicated by numeral 20.

Another pedal construction I9 is shown in Figure 6. In this construction a pedal lever I9 is 3 pivoted at 9 and operatively fixed to one of the first links 19a of the lazy tongs. The operation of the driving means is however not changed.

In the modifications shown in Figures '1 and 8 the boat construction may be similar to that of Figure 1, but the drive for pistons 3 through cables 4 and I4 is somewhat different.

In Figure 7, cable 4 is shown as extending to and partially around a-drum 24 being secured thereto in any suitable manner as at 30. This 40 drum is mounted in suitable bearings and is provided with a gear 23 fixed thereto. Gear 23 is in turn actuatable by means of a longitudinally movable rack 28 operable through pedal It], the operators leg being indicated at Hi.

It is preferred to mount the rack 28 on a series of rollers 2| in order to decrease friction, and these rollers 2| are preferably mounted in a suitable frame 22 fixed to the boat structure.

In the form shown in Figure 8, cable 4 is con- 5 neoted to a sprocket chain 26 actuable by a sprocket wheel 25 and maintained in mesh therewith by a suitable roller 21. In this form, sprocket 25 may be actuated by a rack 26 and small gear 23 in the same manner as drum 24 in Figure 7.

It is of course to be understood that two drums 24 or two sprockets 25 will be provided in each case and actuated alternately as described for the lazy tongs of Figures 1 to 6.

Figures 9 and 10 show a modified form of piston for use with any of the driving means. This piston may be substantially identical with that of Figures 1 to 5 but is shown as provided with anti-friction rollers 3| mounted in its ends so as to decrease resistance, It is preferred to use at least three rollers 3| in each end of the piston as shown.

This application is a continuation in part of my application Serial N0. 666,102, filed April 14, 1933.

Although a specific embodiment of the present invention has been illustrated and described it is to be understood that various changes may be made in the details of construction without departing from the spirit of the invention as set forth in the appended claims, and such changes are contemplated.

What I claim is:-

1. A boat having longitudinal tubular channels below the water line, said channels being open at each end, and piston like plungers in said channels, a rotatable drum, cable means connecting each of said plungers to said rotatable drum, means comprising a pedal operated toothed rack and gear for rotating said drum and thereby propelling the plungers back and forth inside said said channels, a pedal operated toothed rack 1 cable means connecting each of said plungers to the driving end of said rack, sprocket and chain mechanism for propelling the plungers back and forth, inside said channels, said plungers having valves mounted therein, said plungers creating 20 propelling action upon said boat by pushing the water backward in the channels.

KARL F. MARX. 

